Solid phosphoric acid (SPA) catalysts are known for their usefulness in various hydrocarbon conversion processes, such as aromatic alkylation and olefin polymerization. However, there are many problems associated with the use of SPA catalysts. Typical commercial SPA catalysts do not last very long in commercial oligomerization processes because of problems relating to short runs due to deactivation or pressure build-up, or deactivation of the catalyst through the duration of the run. These problems lead to increased temperatures and decreased flow rates which become necessary to maintain conversion. In turn, higher temperatures result in undesirable by-products and increased rates of coking of the catalyst, and slower flow rates result in lower overall rates of production.
There continues to be a great need for catalysts that can operate at lower temperatures and higher flow rates for a longer period of time, resulting in higher conversion levels, lower deactivation rates, and overall higher efficiency in converting hydrocarbons into larger olefins.